Car swing almost finished
The Car Swing is almost finished! At Emile's (MasterMilo) workshop we keep on working on it daily with lots of welding and welding... Slowly all pieces are getting together. Here a photo of the main axle with two pieces of large H-beam attached for connecting the swing and on the side the part for mounting the axle onto the base frame.
This photo shows the assembly of the countermass - laying horizontally to the back - with one of the side arms straight up and connected with a diagonal bar. Inside this countermass fit 6 legio blocks of 450kg concrete each, resulting in total countermass of 2700kg, which should be more than sufficient for balance of the swing.
Here Emile is welding the swing structure to the H-beam pieces to mount the swing to the axle...
...and here the complete assembly of the swing around the axle has been finished. We had to weld plates of 20 mm thick steel with 32 mm holes to the axle for connecting the countermass and side-arms with M30 bolts. For being strong to withstand the large forces, the welds have been built up in multiple layers.
We have now finished the complete swing assembly...
...and have moved all the parts outside for assembly on the base frame. The next step is to mount the car to swing. The videos of the complete production of the Car Swing can be seen at Emile's Werkplaatsvlog.
Car swing on the way
The manufacturing of the Car Swing is taking speed: Emile (MasterMilo) is working daily on the production since the beginning of December. We hoped to have it ready and make the first looping before Christmas, however that turned out not feasible. Now we aim at finishing it during the first weeks of January.
The first photo shows the assembly of one of the small side arms of the swing from H-beams of steel and diagonal bars for strength. The front side will be connected to the central axle while to the far end the cables will be attached.
This is the first set-up of half of the ramp onto which the car will drive when passing by the ground such that it can gain speed. The distance between the two tracks can be adapted and tuned to perfectly fit with the tires of the car.
In the back the large framework is visible onto which the car swing will be mounted. This was already build during the summer and was 'tested' by Emile as a 'normal' swing in which you can swing to go overhead.
At the right of me you can see the large construction onto which the car will be mounted, made of round steel tubes. Below a team photo. The videos of Emile of the complete production of the Car Swing can be seen at his Werkplaatsvlog.
I'd like to present: The Cheerer! A new kinetic sculpture that I have developed in steps during 2022. Around Easter I made the first sketches and investigated the geometry and kinematics and studied the motions. During the summer I made some models and now I have just finished a large version of steel.
The Cheerer expresses the extreme delight after anxiously waiting for something of great desire to happen. For instance at a match, watching in tension and then.....goal! The model in the first photo shows the spectator sitting down watching in suspense, while the second photo shows the spectator in its ultimate cheering position.
The model I made of plastic electricity tube, which is strong, lightweight and easy to process.
A two and a half times larger version of steel I made of 40x40mm steel tubes which are shown here with the holes for the axles.
This photo shows the central axle where multiple parts are connected together.
After assembly of the sculpture also a strong base was made. As a special feature of this sculpture, I want it to actually jump up from its base to be briefly free in the air, like a person jumping up and losing contact with the floor.
The sculpture is driven by a rope to pull the sculpture up. I would like to make some improvements such as installing a handle to actuate the sculpture for a better interaction with a spectator and also the jumping up of the sculpture needs to be optimized by experimental testing. A next step is also to make the sculpture of bronze, as large as the model in the first photos.
[A video of the sculpture cheering will be shown here soon.]
New high-speed robot manipulator
The second secret project I have been busy with during the last months is the development of a new robot manipulator which can move at very high speeds without causing vibrations of its base. The manipulator has been named Super-B, referring to the superb performance due to its Super (inherent) Balance, and has been filed for a patent.
The first photo explains the main elements of the manipulator, which has 2 direct drive motors to control the end-effector for translational pick&place motions within the plane. The key innovation has been the constant inertia mechanism which allows the end-effector to be inherently balanced with two balanced manipulator arms as shown here. The design of the robot has been made by my graduate student Dennis Boere, who investigated a variety of design possibilities for which this one turned out the most advantageous.
The production took quite some time. Here you can see the milling machine for the production of the aluminium end-effector...
... which was glued into carbon-tubes to keep the distal links/parts as light as possible.
The other moving links/parts of the manipulator were made of stainless steel, by tig-welding of lasercutted pieces which fit as a puzzle.
Here the complete linkage is shown during assembly. On all axles bearing tensioners were installed to eliminate the clearance. By carefully designing the masses of all elements, including some additional masses at specific positions, the dynamic balance of the complete linkage was obtained.
The production of the base frame of the manipulator was a challenge on its own, since the distances among the three rotational points need to be very accurate for dynamic balance. Above you can see Dennis fixing the parts before welding and underneath the base is shown during welding.
In this video you can see the mobility of the manipulator after it was fully assembled.
After the assembly we did some experiments for motions with 3 G and 8 G accelerations to verify the dynamic balance and to compare them to an unbalanced situation where the 'no-vibrations indicator' in the first figure was not much silent. The results and the video's of the Super-B are included in a scientific article that will be published soon.
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